Process of coating tin-foil and the resulting product.



A. J. HOWELL. :PROCESS of' comme Tm ron. AND THB RESULTING PRODUCT. APPLICATION FILED APR. 28, 1910.

Patented Nov. 19, B912.

,.1111 l I L ITE v SATES PATENT OFFICEr ALEXANDER J. HOWELL, F SYRACUSE, NEW YORK.

Lili/F356.

To all whiomz't may concern:

Be it known that T, ALEXANDER J. How- ELL, a subject ofthe King of Great Britain, residing at Syracuse, in the county of Onondaga and State of N ew York, have invented certain new and useful Improvements in Processes for Coating Tin-Foil and the lie,- sulting Product, of which the following is a specification.

This invention relates to a process for coating tin-foil with parafiin, and also to the improved material produced thereby.

The principal object of the invention is to secure an even distribution of the paraffin on the surface of the tin-foil in the form of an exceedingly thin sheet or film of paraffin which is associated very closely with the surface of the tin-foil, and will adhere strongly to the surface thereof, and which will bend or fieX with the tin-foil without cracking, chipping or loosening from the surface thereof. To attain this object, `both the tin-foil and paraffin are heated to about the same temperature, a temperature which is sufficient` to melt the paraflin to a liquid state, but not sufficient to melt the tin-foil. An exceedingly thin coat of the melted paraflin is distributed on the tin-foii surface under pressure, and the coated sheet of tinfoil is then permitted to cool.

A preferred form of apparatus capable of carrying out this process, is shown in the accompanying drawings, in which,-

Figure l represents a transverse section through the apparatus on line a a, Fig. 2. Fig. 2 represents a longitudinal section through the apparatus on line Z) b, Fig. l. Fig. 3 is an enlarged detached horizontal f section through one of the side members of the frame for supporting the rollers, on line c c, Fig. l.

In referring tothe drawings, in detail, like numerals designate like parts.

Tn this process, both the tin-foil and the paraffin are heated to a sufficient temperature to melt the paraffin, but not the tin-foil. The parafiin in its melted, or liquid state, is then evenly distributed on the surface of the tin-foil, and the coated tin-foil is then drawn out in a flat condition and permitted to gradually cool. When the coated foil has thoroughly cooled, it will be found that the even layer, or Hlm of paraffin, is very closely associated with the surface of the foil, and adheres very strongly thereto. The heating Specification of Letters Patent.

Application led April 28, 1910.

PROCESS 0F COATING TIN-FOIL AND THE RESULTING PRODUCT.

Patented N ov. i9, 1912.

Serial No. 558,115.

of the tinefoil dries off any moisture or air on the surface or in the pores of the same and thus permit-s a closer and more intimate association of the paraffin -with the tin-foil surface.

The preferred apparatus for carrying out this process is shown in the accompanying drawings, and consists of an outer box or closed receptacle l, having a portion of it-s side 2 hinged to the remainder and adapted to open, as shown in Fig. l, to permit the withdrawal of the tin foil. Within the boX l, is arranged a closed met-al tank 3, the top of which is depressed or recessed to form a pocket or pan 4, in which the paraffin isA melted.

The tank 3 is connected to a suitable source of steam supply by pipes 5. However, other means of heating the tank may be employed.

Two vertical standards 6 extend upward from the opposite ends of the tank, and angular members or parts,'arranged in opposed parallel position, are attached to the inner surface of each standard, as shown in Fig. 3, and form vertical slide ways in which t-he ends of rollers are rotatably mounted, so as to be capable of vertical adjustment.

The lower roller 7, has the ends of 4its shaft rotatably mounted in the slide ways, as before described, and is provided with a peripheral cover 8 of absorbing material, such as cheese cloth, for instance. The lower surface of this roller is immersed in the melted parafiin in the pocket or pan 4. This lower roller will hereinafter be termed the paraffin transferring roller.

Above the paraffin transferring roller is located a roller 9, on which the tin-foil is wound in a long spiral strip. The roller 9 has projecting shaft ends, which are likewise rotatably mounted in the vertical slide ways, so as to have both a'turning movement and a vertical adjusting movement therein.

The tin-foil roller is always held in pressing contact with the paraffin transferring roller by gravity, owing to the weight of the tin-foil. Ordinarily, the weight of the tinfoil roller will be sufiicient to give the desired pressure, and thus secure a very thin layer or coat of the paraffin on the tin-foil. However, a weighted upper roller 10 is illustrated in the accompanying drawings, as arranged above the tinfoil roller. This roller also has projecting shaft ends 11, which are rotatably mounted in the slide ways and also are capable of vertical adjustment therein.

In carrying out the improved process by this apparatus, the tin-foil is drawn olf the tin-foil roller gradually, which slowly turns the lower paraiiin transferring roller and brings the absorbing covering of the parain transferring roller in contact with rthe surface of the tin-foil sheet, and distributes a verythin and even coating of paraffin-on the surface pf the tin-foil. The tin-foil, after it is coated, is drawn out of the box through the opening left by raising the hinged portion of the side of the box, and is cut in suitable lengths and placed in at condition on a table or other suitable support and allowed to cool.

I have found by experience that it is practically impossible to coat a metallic sheet, such as tin-foil, with paraffin while the paraiiin was in a cold unmelted state, as the parailin cannot be rolled thin enough,y or

A forced into the pores or interstices of the tin-foil surface; and furthermore, parafiin cannot be rolled in a cold state under pressure, owing to the fact that it would be broken or cracked up into a multiplicity of fragments. With my process, the paratlin vwhile in a melted state, is distributed upon,

and forced into perfect association with the heated and dried off surface of the tin-foil, thoroughly and evenly coating the surface with an exceedingly thin layer of parain, which when cold, will adhere or stick very strongly to the tin-foil surface, and which will bend or iex in unison with the tinfoil without separating from the surface thereof, or cracking or chipping. This is due to the fact that exceedingly close adhesion is secured between the tin-foil and the film of paraiin, a port-ion of the inner surface of the parain being practically forced into and locked into the pores or interstices of the tin-foil surface.

The improved product, paraffin coated tin- Asurface or in the foil, produced by this process, is utilized chiefly as a medium for incasing unpreserved food products to protect them from contamination by the atmosphere, the paraflin serving to separate and entirely isolate the tin-foil surface from the surface of the food product.

What I claim is:

1. A process for coating tin-foil with paraflin, which consists in melting the paraffin with the application of heat, then coating the heated tin-foil surface with a layer of the melted paraffin under pressure, finally permitting the paraflin coated tin-foil sheet to cool, said paraffin layer being thin enough to be capable of flexing With the tin-foil sheet without loosening therefrom or crack- A process for coating tin-foil with paraimwhich consists in heating both the tinfoil and paraiiin to about the same temperature which is suicient to melt the paraiiin, and dry off any air or moisture u on the ores of the tinoil surface but not sufficient to melt the tin-foil, then coatin heated con ition with av thin layer of the melted paraiiin under pressure, finally permitting the paraflin coated tin-foil sheet to cool, said parain layer being thin enough to be capable of ilexing with the tin-foil sheet without loosening or cracking.

3. A tin-foil-sheet coated with an exceedingly thin layer of paraiiin when both are hot, whereby the paraiinpsurface is in strong and perfect adhesion with the surface of the tin-foil, and is capable of flexing with the tin-foil sheet without loosening therefrom or cracking.

In testimony whereof I affix my signature in presence of two witnesses.

ALEXANDER J. HOWELL.

Witnesses EUs'rAoE C. OWEN, J. M. GUNNELL.

the tin-foil surface while in a` 

